Bicycle frame



FIG. 1 is a side elevation view of a bicycle frame showing my new design;

FIG. 2 is a perspective view thereof shown from the top, rear and one side; and,

FIG. 3 is a perspective view thereof shown from the bottom, front, and same side as FIG. 2, the opposite side being a mirror image of that shown in FIGS. 1-3. 

The ornamental design for a bicycle frame, as shown and described. 